1. Field of the Invention
The present invention generally relates to a wireless power transmitting unit, a wireless power receiving unit, and control methods thereof, and more particularly, to a wireless power transmitting unit, a wireless power receiving unit, and control methods thereof, which can wirelessly transmit/receive charging power.
2. Description of the Related Art
Wireless charging or non-contact charging technologies have been developed to be currently used for many electronic devices. Such a wireless charging technology employs wireless power transmission/reception, and corresponds to, for example, a system in which a battery can be automatically charged if the battery is placed on a charging pad, without the need for connecting the electronic device to a separate charging connector. The wireless charging technology can increase a waterproof function through wirelessly charging electronic products and increase portability of the electronic device because there is no need for a wired charger.
Among the wireless charging technologies, charging using a resonance scheme is performed as follows. When a wireless power receiving unit (for example, a portable terminal) requiring charging is located on a wireless power transmitting unit (for example, a charging pad) transmitting wireless power, the wireless power transmitting unit may charge the wireless power receiving unit. When a plurality of wireless power receiving units are located on a charging area of one wireless power transmitting unit, power required by each of the wireless power receiving units may be different from the transmitted power, so that efficient charging can be made for each of the wireless power receiving units.
While research on a wireless charging method is currently progressing, standards for a wireless charging order, a search for a wireless power transmitting unit/receiving unit, selection of a communication frequency between the wireless power transmitting unit/receiving unit, a wireless power control, selection of a matching circuit, and communication time distribution to each wireless power receiving unit in one charging cycle have not yet been proposed. Specifically, there is a need for a technology which can deal with a situation where the wireless power receiving unit detects a charging environment change by notifying the wireless power transmitting unit of the detected environment change.